Unimolecular decomposition of ethyl lactate, CH3CH(OH)COOC2H5, upon electron impact

Takahashi, Yutaka; Higuchi, Tetsuo; Sekiguchi, Osamu; Hoshino, Mamoru; Tajima, Susumu

doi:10.1016/s1387-3806(98)14178-7

Cited by 6 publications

(9 citation statements)

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“…To further investigate the mass spectrometry behavior of ethyl lactate, we decided to undertake a thorough mechanistic study based on computational chemistry using DFT calculations. Takahashi et al reported a mechanistic study dealing with the unimolecular decompositions of ionized ethyl lactate using mass-analyzed ion kinetic energy spectrometry (MIKES). , In this paper, they mainly focused on the m / z 75 ions, arising from a C 3 H 7 • loss, and they tentatively proposed, without any theoretical support, that those C 3 H 7 O 2 + fragment ions are produced from the ethyl lactate molecular ions following a double hydrogen migration (DHM) rearrangement. , …”

Section: Results and Discussionmentioning

confidence: 99%

“…Starting then from ionized ethyl lactate, four dissociation pathways are likely to occur to account for the production of the detected ionic species, see Figure . ,,− Single bond cleavage processes, namely the α-cleavages, characteristic of carbonyl compounds were calculated to require 0.64 and 1.37 eV, respectively, for the isomeric CH 3 CH(OH) • and CH 3 CH 2 O • losses (Figure , red and blue, respectively). These two reactions yield isomeric CH 3 CH 2 OCO + and CH 3 CH(OH)CO + acylium ions both detected at m / z 73.…”

Section: Results and Discussionmentioning

confidence: 99%

“…The presence of an H γ in ethyl lactate immediately suggests the presence of a McLafferty rearrangement. ,,− Such a reaction is initiated by the migration of the H γ to the oxygen atom of the carbonyl moiety affording a distonic radical cation. It is really interesting to note that the corresponding level is located only 0.35 eV above ionized ethyl lactate (Figure , green).…”

Section: Results and Discussionmentioning

confidence: 99%

“…The corresponding internal energy excess was also calculated and is shown in Figure (dashed brown line). It appears that, upon vertical ionization, ,,− the molecular ions of ethyl lactate are generated with an 0.8 eV internal energy excess. In first approximation and ruling out other excitation processes, such an energy content exceeds the energy requirements for cleavage α1 and for the McLafferty rearrangement to occur.…”

Section: Results and Discussionmentioning

confidence: 99%

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Combining Mass Spectrometry Diagnostic and Density Functional Theory Calculations for a Better Understanding of the Plasma Polymerization of Ethyl Lactate

et al. 2014

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The focus of this work is on the growth mechanism of ethyl lactate-based plasma polymer film (ELPPF) that could be used as barrier coatings. In such an application, the ester density of the plasma polymer has to be controlled to tune the degradation rate of the material. Our strategy consists of correlating the plasma chemistry evaluated by RGA mass spectrometry and understanding, via DFT calculations, the chemistry of the synthesized thin films. The theoretical calculations helped us to understand the plasma chemistry in plasma ON and OFF conditions. From these data it is unambiguously shown that the signal m/z 75 can directly be correlated with the precursor density in the plasma phase. The combination of XPS and chemical derivatization experiments reveal that the ester content in the ELPFF can be tailored from 2 to 18 at. % by decreasing the RF power, which is perfectly correlated with the evolution of the plasma chemistry. Our results also highlight that the ELPPF chemistry, especially the ester content, is affected by the plasma mode of operation (continuous or pulsed discharge, at similar injected mean power) for similar ester content in the plasma. This could be related to different energy conditions at the interface of the growing films that could affect the sticking coefficient of the ester-bearing fragments.

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Section: Results and Discussionmentioning

confidence: 99%

Section: Results and Discussionmentioning

confidence: 99%

Section: Results and Discussionmentioning

confidence: 99%

Section: Results and Discussionmentioning

confidence: 99%

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Combining Mass Spectrometry Diagnostic and Density Functional Theory Calculations for a Better Understanding of the Plasma Polymerization of Ethyl Lactate

et al. 2014

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“…The decomposition scheme of EL has been studied using several characterization techniques, including mass spectrometry, [ 12,25 ] X‐ray photoelectron spectroscopy, [ 10 ] and electrical characterizations. [ 6 ] In this study, Fourier‐transform infrared (FTIR) absorption spectroscopy was used.…”

Section: Introductionmentioning

confidence: 99%

Fourier‐transform infrared spectroscopy of ethyl lactate decomposition and thin‐film coating in a filamentary and a glow dielectric barrier discharge

Milaniak

Laroche

Massines

2021

Plasma Processes & Polymers

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Glow and filamentary regimes of atmospheric pressure plasma‐enhanced chemical vapor deposition in a planar dielectric barrier discharge configuration were compared for thin‐film deposition from ethyl lactate (EL). EL decomposition in the plasma phase and thin‐film composition were both characterized by Fourier‐transform infrared spectroscopy. EL chemical bonds' concentration along the gas flow decreases progressively in the glow dielectric barrier discharge (GDBD), whereas it drastically oscillates in the filamentary dielectric barrier discharge (FDBD), with values higher than that of the initial mixture. EL decomposition route depends on the discharge regime, as the decrease of the concentration of the different investigated bonds is different for an identical amount of energy provided to EL molecules. CO2 is systematically formed reaching concentrations of 25 and 40 ppm, respectively, in FDBD and GDBD.

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Formation and decomposition of the m/z 75 fragment ions from the molecular ion of ethyl lactate, CH3CH(OH)COOCH2CH3

Tajima

Watanabe

Nakajima

et al. 2001

International Journal of Mass Spectrometry

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Unimolecular decomposition of ethyl lactate, CH3CH(OH)COOC2H5, upon electron impact

Cited by 6 publications

References 37 publications

Combining Mass Spectrometry Diagnostic and Density Functional Theory Calculations for a Better Understanding of the Plasma Polymerization of Ethyl Lactate

Combining Mass Spectrometry Diagnostic and Density Functional Theory Calculations for a Better Understanding of the Plasma Polymerization of Ethyl Lactate

Fourier‐transform infrared spectroscopy of ethyl lactate decomposition and thin‐film coating in a filamentary and a glow dielectric barrier discharge

Formation and decomposition of the m/z 75 fragment ions from the molecular ion of ethyl lactate, CH3CH(OH)COOCH2CH3

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